Objectives: To evaluate the effect of a shared care programme (SCP), defined as a scheme based on shared responsibility, enhanced information exchange, continues medical education and explicit clinical guidelines, between general practitioners (GPs) and a hospital outpatient clinic (HOC), on oral anticoagulant therapy (OAT).
Design: The study was a 2-year prospective, randomized, controlled trial, preceded by a 1-year period of observation.
Setting: The HOC, GPs, and OAT patients in the admission area of Aarhus University Hospital, Aarhus County, Denmark, covering 310 300 inhabitants.
Subjects: A total of 207 GPs, including their enlisted patients on OAT, were invited, and 61.4% accepted participation. They were randomized into an intervention group [group-INT: 64 GPs and 453 patients (170 patients on OAT throughout the study period, i.e. full follow-up)], and a control group [group-CON: 63 GPs and 422 patients (173 with full follow-up)]. The remaining 80 GPs served as a nonresponder group (group-NON) of 485 patients (184 with full follow-up).
Main outcome measure: Therapeutic control of OAT in terms of time spent by the patients within the therapeutic interval (TI) of an international normalized ratio (INR) between 2.0 and 3.5.
Results: The groups did not differ significantly with regard to age, sex, OAT indication, anticoagulant drug used, or the therapeutic control at baseline. In a comparison based on intention-to-treat principles, the therapeutic control increased statistical significance amongst patients with full follow-up in group-INT compared with group-CON (median time within TI: group INT = 86.6% vs. 80.5%, P = 0.007).
Conclusion: An SCP of anticoagulant management is effective in reducing patient time outside the therapeutic INR interval in OAT patients randomly assigned to an SCP, as compared with a control group.